Dynamo frame



Oct. 13, 1925.

Y E. R. KUHLs DYNAuo FRAME Filed Nov. 18. 1924 Patented Oct. 13, 1925.

.UNITED STATESV PATENT OF 1,557,090 F l C E.

Elm RUBIS, Ol' DAYTON, OHIO, ASSIGNOB TO THE DAYTON ENGINEERINGLABORATORI COHPANY, OF DAYTON, OHIO, A. CORPORATION OF. OHIO.

DYNAMO FRAME.

Application lled November 18, 1984. serial No. 750,645.

' To all whom it may cof/wm.'

Be it known that I, ERNEST R. KUHLs, a citizen of the United btates ofAmerica, residing at Dayton, county of Montgomery, and State of Ohio,have invented certain new and useful Improvements in Dynamo Frames, ofwhich the following is a full, clear, and exact description.

This invention relates to construction of frames for dynamo electricmachines and includes among its objects a method of manufacture ofdynamo frames by which the cost of manufacture may be substantiallyreduced.

Other and further objects and advantages of the present invention willbe apparent from the following description of a preferred form thereof,reference being made to the accompanying drawings.

Fig. 1 of the drawings is a longitudinal sectional view ofia dynamofield frame constructed in accordance with the present invention. Fi s.2 and 3 are end views looking in the dlrection of the arrows 2 and 3,respectively, in Fi 1. Figs. 4 and 5 are sectional views ta enrespectively on the lines 4-4 and 5-5 of Fig. l.

The dynamo frame includes a tubular member 20, whichgprovides the fieldframe. This frame may be made from sections of iron pipe or may beformed from flat sheet iron into a cylinder havin a welded seam. rIheframe is provided with one or more openings 21, adjacent one end thereofto provide access to the commutator and brushes which are to besupported within the tubular member 20. Heretofore, it has been thepractice to turn or grind the interior wall of such tubular members inorder to provide a true cylindrical surface against which the polepieces are bolted, and which provides for the correct location of theend frames laterally with respect.I to the field frame. The presentinvention eliminate this expensive machine operation.

Before machining the frame 20 is approximately cylindrical and its endsurfaces are onl approximatelyV plane and parallel to eac other. Thetubular member 20 is rovided with finished end surfaces 22 an 23 whichare parallel to each other and at right 'l angles to the approximateaxis of the memnal extending, arallel grooves all at right angles to thep ane end surfaces 22 and 23. Each groove is defined by a bottom surface24 and side surfaces 25 and 26. The distance between these side surfacesis slightly greater than the width of the`shank of the pole piece 27which the groove is to receive. The bottom surfaces 24 are cylindricaland coincide with a common cylindrical surface, the axis of whichcoincides with the axis of the cylinder shaft which the frame isintended to support.

The pole pieces 27 are cut from lengths of specially rolled iron havingthe desired cross section as shown in Fig. 5. The shank of each polepiece 27 has a cylindrical side surface, conforming with and engagingthe groove bottom surface 24. But one screw 28 is necessary to secureeach pole piece 27 to the tubular frame member 20, since lateraldisplacement of the pole piece is prevented by the side surfaces 25 and26 of the groove which receives Ithe shank of the pole piece. As shownin Fig. 5, pole pieces 27 present pole faces 29 which are equidistantfrom the common axis of the cylindrical surfaces 24 of the grooves andare therefore equidistant from the axis of the dynamo shaft which is tobe supported b the frame.

Against the en surface 22 of member 2O there is secured an end frame 30which includes a plane annular flange 31 adapted to contact with the endsurface 22. The end frame 30 includes a tubular extension 32 forreceiving a shaft bearing 33, the axis of which is at right an les tothe flange 31. In order to locate the earing 33 centrally of Ithe polefaces 29, the frame 30 is provided with members cooperating with thegrooved bottom surfaces 24 for preventin lateral displacement of theframe 30 and or locating the bearing 33 so that its axis will be locatedparallel to and centrall of the pole faces 29,. These locating mem ersare provided by the radially extending projections 34 of a disc 35. Theedges of these projections 34 are arcuate and are equidistant from acentral sleeve portion 36 of the disc 35 which is adapted to receive theshaft bearing 33. The disc 35 is secured to the end frame 30 by rivets37, which also secure brush brackets 38 and bracket insulation 39 to theend frame 30. The distance between the diametrically opposite edges ofthe pro-- jections 34 is substantially equal to the dis tance betweendiametrically opposite rtions of the groove bottom surfaces 24. t istherefore apparent that when the frame 30 is secured a ainst the endsurface 22 of the member` 20 the shaft bearing 33 will be locatedtlarallel to and centrally of the faces 29 of e pole ieces 27.

Against t e end surface 23 of the tubular frame member 20 there issecured an end frame 40 having a plane annular rfportion 41 ada ted to-engage the end su ace 23. Centra ly thereof the frame 40 supports asleeve 42 provided with a shaft bearing 43, the axis of which is pedicular to the portion 41. In order to ocate the bearing 43 centrallywith respect to the le faces 29, the frame member 40 is provided withlugs 44 which are cut from and bent away from the main portion of theframe 40. Each lug terminates in an arcuate edge 45 and all the edges 45are equidistant from the axis of the shaft bearing 43. The vdia metrical-distance between oposite edges 45 is substantially equal to the'ametrical distance between opposite groove bottom surfaces 24.Therefore, when the frame 40 is secured against the end surface 23 ofthe tubular member 20 the axis of the shaft bearin 43 will be locatedparallel to and centra y of the ole faces 29, and also in alignment witht e axis of the shaft bearin 33.

e frames 30 and 40 are s'ecured in position by bolts and nuts 51.

From the foregoing description it is agarent that the cost ofmanufacture of t e dynamo has been materially reduced by rea son of thesimplicit of construction and by a method of manu acture whicheliminates many of the expensive machine operations which heretoforehave been performed. As alread mentioned, it has been the practice to mae the entire interior surfaces of the tubular frame member perfectllindrical in order to provide surfaces or ocating the end frames andpole pieces. The method disclosed herein provides for machining theinterior surfaces of the frame member at only a suicient number ofplaces to locate the end frames and pole ieces. the remaining portionsof the interior of the tubular frame member being unfinished.

Pole pieces formed from sections of specially rolled iron bars have beenfound satisfactory since these bars can be rolled fairly uniform withrespect to cross sectional d1- mensions. The cylindrical surfaces ofthese bars are sufficiently exact so that no machine operation isrequired. The pole pieces are merely cut off from lengths of bar stockand are drilled and tapped to receive the securing screws 28.

The end frames 30 and 40 of the disc are constructed preferably of flatsheet material and can be struck up by suitable punches and dies intethe desired shape very ra idly. These frames are provided with radi yextended and strengthening ribs as indicated in Figs. 1 and 2. Thebearings 33 and 43 are press fitted within the tubular portions 32 and36, and the tubular portion 42 respectively.

While the form of embodiment of the present invention as hereindisclosed, constitutes a preferred form, it is to be understood thatother forms might be ado ted, all com` within the scope of the c aimswhich fo ow.

What I claim is as follows:

1. A dynamo frame comprising in combikvnation a tubular member havingparallel end surfaces and interior] thereof, a luralit' of spaced,longitu all exten 'ng para el locating surfaces at ri t angles to theend surfaces; a lurality of pole pieces secured to the tubu r member,the shank of each pole piece engaging a locating surface, the pole ieceshaving their faces equidistant from t e axis of the shaft to be suported by the frame; and end frames eac secured a ainst an end surfaceof the tubular mem r and having spaced locating members each terminat.in a surface adapted to engige one of e locati surfaces of the tu u armember, and eac having a shaft bearin so related to the locating membersthat t e shaft bea will be in alignment and located cent y of the facesof the pole pieces when the end frames are assembled upon the tubularmember.

2. A dynamo frame comprising, in combination a tubular member havingparallel end surfaces and, interiorly thereof, a luralit of spaced,longitudinally exten para lel grooves at right angles to the en surfaceshaving bottom surfaces equidistant from the axis ofthe shaft which theframe is intended to support; a plurality of identical pole pieces eachhaving a shank bottoming in a groove; and end frames each securedagainst an end surface of the tubular member andhavi a shaft bearing atright angles tothe en surface and having spaced locating membersterminating in surfaces aecluidistant from the shaft bearing and each ated to bottom in one of the grooves of the tu ular member.

3. A dynamo frame comprising, in combination a tubular member havingparallel end -su aces and interiorlv thereof, a luralit of spaced,longitudinally exten ing para lel ves at ri t angles to the en surfacesaving cylin rical bottom surfaces equidistant from the axis of the shaftwhich the frame is intended to support; a plurality of identical polepieces having a shank provided with a correspondingly cylindricalsurface adapted to bottom in a groove; and end frames each securedagainst an end surface of the tubular member and having a shaft hearingat right angles t0 the end surface and having spaced locating membersterminating in cylindrical surfaces equidistant from the shaft bearingat a llistance substantially equal to the radius of curvature of thegrooves.

4. A dynamo l'raine comprising, in combination, a tubular melnher havingan approximately cylindrical interior Surface provided with parallelgrooves having cylindrical bottoni surfaces of the saine radius ofcurvature and eqnidistant l'roni the axis of the shaft which the frameis intended to support; and eiul frames eaeh having a shaft hearing :unlcxleiuliug radially therel'roni a plurality of locating nielnbersterminating in locating laurl'accs having a coininon radius ot'curvature. centering in the axia` ol the lahal'lI hearing aiulsubstantially thc sanne radius as the curvature. ol the botlonis ol' thegrooves.

ln tesliinony whcreoll l hereto allix iny signature.

ERNEST R. KUHLS.

